1. Field of the Invention
The present invention generally relates to a keypad panel, and more particularly to a metal keypad panel structure.
2. Description of Prior Art
As communication technologies advance continuously, many electronic products are manufactured with a light, thin, short and small design to reduce the size and weight of the electronic products and facilitate users to carry the electronic products. To reduce the size and weight of an electronic product, designers and manufacturers reduce the volume of internal integrated circuits as well as the area and thickness of the operating interface on a surface of the electronic product before the electronic product is installed to a communication device.
Referring to FIGS. 1(a) and 1(b) for a traditional metal keypad panel as disclosed in U.S. Application Pat. No. 2007/0205986A1, the metal keypad panel 10a of this patent application includes an elastic layer 1a, a side of the elastic layer 1a includes a plurality of protrusions 11a, another side of the elastic layer 1a corresponding to the protrusion 11a includes a plurality of metal press keys 2a, each of the metal press keys 2a has a hollow portion 21a with a corresponding pattern, and a light transmitting resin layer 22a is filled into the hollow portion 21a. When the metal keypad panel 10a is installed into a base 20a of an electronic device, the metal keypad panel 10a is situated on the electric signal module 30a, and the electric signal module 30a has a printed circuit board 31a, the printed circuit board 31a has a plurality of immovable contact points 32a disposed thereon, and a metal plate 33a is installed onto the circuit board 31a. The metal plate 33a has a plurality of domes 331, each dome 331a with an arc surface corresponds to each contact point 32a, and another side of the dome 331a corresponds to the protrusion 11a. If the metal press key 2a is pressed, the protrusion 11a is pressed onto the surface of the dome 331a to deform the dome 331a and contact with the contact point 32a to generate an electric signal output. When the backlight source is lit, the light of the backlight source can be passed through a resin layer 22a of the metal press key 2a to allow users to see the position of each press key clearly.
Although the metal keypad panel 10a is manufactured with a light, thin, short and compact design and can be installed and used in a small electronic device, its manufacture requires filling a resin layer 22a to a hollow portion 21a of all metal press key 2a one by one, and then attaching the metal press keys 2a precisely onto a side of the elastic layer 1a one by one, thus the manufacture of the metal keypad panel 10a takes much time and effort and technically involves a high level of difficulty. After the metal keypad panel 10a is assembled and combined with the base 20a, a gap is formed between the periphery of the metal press key 2a and the base 20a, thus dusts may be accumulated at the exterior of the keypad panel 10a or water may enter into the interior easily, and finally causing an unsmooth operation of the press keys or a short circuit to the internal circuits. Furthermore, there is no reflective effect of any bright line on surfaces of the metal keypad panel 10a, so that the metal keypad panel 10a is extremely dull in appearance.